An Evening With Mr Evison

Last Wednesday evening, Threadspider and I decamped to our local garden centre for the evening for a talk by Raymond Evison on Clematis for Today's Gardens. Naturally, we managed some light retail therapy beforehand, combined with frequent sightings of the great man as he was being given a guided tour of the garden centre at the time. It must have been quite strange for him as every nook and cranny of the garden centre was filled with posters, like the one above, advertising the talk.

He greeted everyone as they arrived, which was a really nice touch. It was even nicer when he recognised me from our previous encounters at Chelsea and the RHS Inner Temple Show. This time I was able to confide it was indeed this very spot where I'd purchased my sports of C. 'Josephine' (left) and C. 'Crystal Fountain' (below, right) :)

It was an inspiring talk. We were treated to a whistle stop tour of over 50 cultivars of all shapes and sizes, with ideas for using them in large borders; scrambling down banks and through trees; ones for small spaces; over arches; layered combinations; and lots of ideas for pots. I particularly liked the idea used at Wisley where 6ft twiggy birch branches are used as pot supports instead of the traditional obelisk. Of course there were lots of ideas for planting combinations. I found C. montana 'Broughton Star' with Copper Beech; C. 'Wisley' (purple) with a golden hop; and C. 'Josephine' with pale pink Astrantia most striking: the slide of this last combination drew an oooooh of approval from the audience.

We also had some tantilising insights into breeding Clematis. Around 2,500 crosses are made at the nursery in Guernsey each year which yields about 30,000 to 35,000 seeds. About a third of these germinate and then the 8-10 year process of growing on, selecting the most promising, trialling them in various conditions all over the world and finally launching a tiny few - just 3 cultivars at Chelsea this year - ensues. C. 'Fleuri' (see right) was my favourite from Chelsea.

As well as the breeding programme, chance also plays a major role: C. 'Josephine' is one such example, having been found on a market stall in London and mistreated for a number of years before the lady who bought it persuaded Raymond Evison it was a most worthy plant. C. 'Crystal Fountain' (see picture left) was found in Japan and C. 'Freckles' in Mallorca - the latter is named for his eldest daughter!

The breeding programme is looking for very free-flowering Clematis which bloom along most or all of the stem for as long a period as possible. A number of different flowering heights are being encouraged, though most recently the emphasis has been on selecting for shorter plants growing to a height of 4ft (e.g. C. 'Cezanne') for growing in pots or even shorter, around 1ft (e.g. C. 'Bijou') for ground cover. Of course by breeding plants to grow at various heights, it also means I now have the mouth watering prospect of layered Clematis combinations to think about!

All too soon the talk was over, though there was also plenty of time for questions at the end. I'm most relieved to find that my not pruning of my C. 'Freckles' - (see right) which I thought was the correct thing to do for evergreen Clematis - so that she's now a sprawling mess is redeemable and that her habit of flowering at various times of the year - like she is now - as well as her usual winter season is quite normal.

Top Tips from the evening:

• Pre-soak plants for 20 minutes prior to planting
• Choose deep colours or white flowers for bright, sunny positions; pale colours for shady or north facing situations
• If planting in a pot, don't use plastic as this will be too hot for the roots in the summer. For larger Clematis 18 x 18" pots should be used; the newer short growing Clematis like C. 'Bijou' (growing to 12 inches) can be planted in a 12 x 12" pot. Make sure the pot used has very good drainage - if rainy, it should be raised up on pot feet
• Grow bedding at the feet of potted Clematis to ensure the bottom of the plant is kept in cool conditions
• A 4ft high pot-grown Clematis (in an 18 x 18" pot) should give a good display for at least 5 years before needing repotting
• C. 'Petit Faucon' is particularly good for gardens with hot conditions - it withstood temperatures of 90 degrees (fahrenheit) in trials in South Carolina. C. Harlow Carr is another good one for heat - it's done well in California
• September is a great time for planting in Britain as there are a couple of months for the plant to get well established before the cold weather starts
• In the first spring after planting, the plant should be chopped down to 12", irrespective of pruning group. This encourages lots of shoot formation and bushy growth. Cultivars in the new compact 'Boulevard' range (bred for pots and grow to about 4 feet in height) can have the 'pony tail chop' treatment each year i.e. grab hold of all the stems at once and cut them off at 12"
• Feed with tomato or rose feed

This must-have book's going on my list for that word-beginning-with-C-which-doesn't-exist-until-December ;)